1. Field of the Invention
The present invention relates generally to methods for state estimation and more specifically it relates to a method of power system state estimation for effectively and accurately identifying topology errors, parameter errors and measurement value errors for power networks in real-time.
2. Description of the Related Art
Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field.
The power industry is urgently looking for new state-of-the-art state estimators to improve the security and avoid the occurrence of blackouts. The problem with the current power systems state estimator/monitor has existed for about 50 years, and has caused a lack of monitoring of power systems and hence a number of problems in power system operations. The August blackout in 2003 is an example of this. It forced the industry to solve this challenging problem.
The August Blackout, which lasted for 30 hours and heavily impacted the US Northeast region, costs the American business economy about $10 billion dollars in losses. The Presidential task force concluded that, “The initial problem was a software program glitch”. The monitoring computer running the standard state estimation procedures in Ohio “hung-up” and “froze” and the operators became blind to the issues in the transmission network but did not do anything in the precious period before the occurrence. However, that was only a reflection of the modern state of affairs in power grid vulnerabilities. According to Bob Galvin, the retired CEO of Motorola, roughly 500,000 Americans spent at least two hours without electricity in their homes and businesses. These outages cost our economy $150 billion a year, The exact number of these blackouts that are due to the faulty computer monitoring is unknown but many power grid control centers acknowledge regular daily or weekly computer “glitches”.
State estimation is a critical and vital function for electrical power grid control at the center of operations. Since the conception and use of state estimation for power grid operational management during the 1970's, it has been assumed that the method always produces a reliable and accurate real-time power flow status and modeling representations we know to be true except under condition of normal power glow. Under condition of high stress of transmission systems have been shown to fail consistently. The inaccuracy and unavailability of state estimation have large negative influences on the market price calculation and security assessment, two very important functions in power system operations. The inherent flaw in the commonly used weighted least square (WLS) state estimation is the root reason of the inaccurate and unavailability of state estimation. Continuous efforts from researches and engineers have been made to attempt to solve this challenging problem of WLS for decades. The present invention provides a revolutionary state estimation approach which would replace the existing state monitors.
Because of the inherent problems with the related art, there is a need for a new and improved computer-based method of power system state estimation for effectively and accurately identifying topology errors, parameter errors and measurement value errors for power networks in real-time.